relationship-tracker

該有的功能都實現了。Grok 一步步神奇地變出我想要的功能。

真的能用下去嗎？自己的數據庫好像很靠不住。不過既然可以導入數據，繼續用原本的方法記錄也沒關係。

https://github.com/Evthron/RelationshipTracker

Structure

MainActivity -> MainScreen -> MainViewModel -> AppDatabase -> Dao -> Entities

Syntax

var Mode by remember {mutableStateOf("")}
lambda expression
- viewModel.getAllConversations().collectLatest { conversations = it }
- ‘Set conversations = the what the function returns’
- viewModel.getAllConversations().collectLatest { fetchedConversations -> conversations = fetchedConversations}
flow
- Flow<List>
- collectLatest

Compose

Surface
- Theme
- modifier
Scaffold
- topBar
- botttomBar
- padding -> send the padding to child objects
on
- onDismiss
- onClick
- LaunchEffect

ViewModel

- interact with database
- factory
- Generic type, subclass of Viewmodel
- \<T: Viewmodel\> create(MainViewModel::class.java)

Room Database

- Entity
- data class
- enum class
- Data access object (dao)
- Non-entity data class (fast access without creating redundancy)

suspend
- used whenever a query is performed, all subsequent function is required to be suspend.
- suspend fun insert()
- must be called from a coroutine?
- cannot freely called
flow
- Flow<List<Person>>
- auto update when data changes
annotations
- @Insert, @Update, @Delete
- @Query

LaunchEffect not executed

In MainScreen.kt:

// Collect conversation data
    LaunchedEffect(viewMode, selectedTag) {
        Log.d("MainScreen", "Collecting conversations: " +
                "viewMode=$viewMode, " +
                "selectedTag=$selectedTag"
        )
        if (viewMode == "AllConversations") {
            if (viewMode == "AllConversations") {
                val conversationsFlow = selectedTag?.let { viewModel.getAllConversationsByTag(it) }
            if (selectedTag == null) {
                combine(
                    viewModel.getAllConversations(),
                    viewModel.getAllConversationStats(),
                ){
                    convs, stats ->
                    conversations = convs
                }
                viewModel.getAllConversations().collectLatest {
                    conversations = it
                    Log.d("MainScreen", "Updated all conversations: ${it.size} items")
                }
            } else {
                viewModel.getAllConversationsByTag(selectedTag!!).collectLatest {
                    conversations = it
                    Log.d("MainScreen", "Updated filtered conversations: ${it.size} items")
                }
            }
            viewModel.getAllConversationStats().collectLatest {
                conversationStats = it
                Log.d("MainScreen", "Updated conversation stats: $it")
            }
        }
    }

When any one of the collectLatest is triggered, the code after that will not run. Possibly because it triggered the LaunchedEffect function once again interrupted the flow, but I can’t find the exact cause.

reworked the code using combine

// Collect conversation data
    LaunchedEffect(viewMode, selectedTag) {
        Log.d("MainScreen", "Collecting conversations: " +
                "viewMode=$viewMode, " +
                "selectedTag=$selectedTag"
        )

        if (viewMode == "AllConversations") {
            // Determine the conversations flow based on selectedTag
            val conversationsFlow = selectedTag?.let { tag ->
                viewModel.getAllConversationsByTag(tag)
            } ?: viewModel.getAllConversations()

            // Combine both flows
            combine(
                conversationsFlow,
                viewModel.getAllConversationStats()
            ) { convs, stats ->
                // Update both values together
                conversations = convs
                conversationStats = stats

                // Log updates
                Log.d("MainScreen", "Updated conversations: ${convs.size} items")
                Log.d("MainScreen", "Updated conversation stats: $stats")
            }.collect() // Collect the combined flow
        }
    }